Door closer



Dec. 19, 1939. L. coRNWELl.

DOOR CLOSER Filed Jan. 3l, 1958 g Cergy Cornwell Bnventor Patented Dec. 19, 1939 UNITED STATL iFATENT OFFICE 2 Claims.

My present invention relates to improvements in door closers of the spring and lever operating type with which is employed a pneumatic check to control the closing of the door.

The primary purpose of this invention is the means provided whereby the door, after being opened manually and automatically swung toward closing position by the tension of the spring against the pneumatic check, is snapped shut to effect the locking of the latch.

I am aware of the several prior spring lever and pneumatic types of door closers, and therefore my present invention is directed principally toward means for insuring the locking of the door when it is automatically closed.

Other improvements and objects closely related to the closing means will be hereinafter fully set forth and claimed.

The invention is primarily adapted for use on swinging doors, as for example, doors between rooms, outside doors, and screen doors, and broadly consists of a pivoted lever adapted to reciprocate a spring pressed plunger or piston within a pneumatic cylinder and a by-pass in the cylinder effecting a quick release of air under pressure when the door is near closed position.

The invention consists in certain combinations and arrangements of these parts as will be hereinafter more specifically described and claimed.

In the accompanying drawing I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best mode I have thus far devised for the practical application of the principles of my invention, but it will be understood that changes and alterations may be made in the exemplied structure withinv the scope of the appended claims without departing from the principles of my invention.

In the drawing:

Figure 1 is a side elevation of the closer of my invention.

Figure 2 is a vertical sectional View of the closer showing the parts in their normal position as when the door is closed.

Figure 3 is an end view of the closer showing the device of my invention mounted upon a door jamb and attached to a door.

Figure 4 is an enlarged perspective View of a portion of the cylinder showing the bly-pass therein.

Referring now to the drawing, l illustrates the cylinder of my device. The cylinder, preferably of metal, is provided with longitudinal, diametrically opposed slots 2 and 2 adjacent one end of the cylinder. Exterior of the cylinder and proximate the outer end of the slot 2 I have formed a pair of spaced lugs 3 and 4 having openings therethrough adapted to receive the bolt 5. A nut as 5 is provided for the bolt to retain the 5 bolt in position. Jcurnaled upon the bolt 5 I provide the lever formed generally in a compound curve extending through the slots 2 and i cf the cylinder and provided with pivotal means, as the attaching plate l, which plate is l@ adapted to be secured upon a door D.

lever 5 on its bearing face '3' is provided with indentations or notches 8 and 9 for engagement-with the roller Iii as will be hereinafter more fully described.

The slotted end of the cylinder is closed by means oi a fricticnally retained cap li, and the opposed end of the cylinder is closed as by means of a irictionally retained cap l2. This cap i2 is fashioned with a perforate lug extension i3 of 2U considerable depth through which is journaled the bolt id having an attaching plate l5 on one end thereof. The plate l5 is provided with screw holes i6 and it by means of which the plate i5 is securely attached to a door jamb as J. The 'nc-lt l@ is retained as by a nut l'l thereon.

The cap l2 is also provided with an air Valve, as .ne tapered bolt i8 threaded into the hole i9, providing an adjustable vent for the air under pressure in the cylinder to permit the closing of :o the door.

Adapted to reciprocate within the cylinder I,

I have provided the piston P comprising the piston rod 2Q having a piston head including the spaced retaining nuts 2l and 22, and spaced f, washers 23 and Between the washers 23 and I provide a sealing disk 25 of flexible and durable material as leather, having the ange 25 fashioned in such a manner as to seal the piston in the cylinder and prevent the passage of air thereby.

Approximately central of the longitudinal length of the cylinder is fashioned an interior annular ridge 29 and this ridge forms the retaining means for the disk 32 slidably mounted 45 on the piston rod 25J.

A coiled spring 3l is mounted about the piston rod 2t' and between the disk 3i] and the washer 23 providing for the automatic return of the piston when the piston has been reciprocated against the tension of the spring.

The opposite end of the piston rod 20 is threadedly secured in a block 28 slidably mounted in the cylinder exterior of the pressure chamber and having a cam surface 21. The roller IU aforementioned is rotatably mounted on this block 2S spaced from the said cam surface.

It will be apparent that the door is maintained in open position due to the fact that the roller lil engages the notch 8 of the operating arm 6, and the pressure which is exerted by spring 3l interposed between the Washer 3D and the piston. When the pressure is released, of course, the spring tension overcomes the frictional Contact between the notch 8 and the roller I0 and the door is swung toward closed position.

Near the valved end of the cylinder is fashioned a loy-p-ass comprising a struck out portion or depression 32. This by-pass is formed at an angle to the longitudinal center of the cylinder in such a manner that the disk 25 of the piston head may not be deformed in passing thereover. The by-pass in its angular position extends over a greater longitudinal length of the cylinder than does the sealing disk iiange 25' and thus it will be seen that when the flange 25 of the ydisk 25 passes over the by-pass, air under pressure will pass around the flange 25' and instantaneously release the pressure of air, and the piston will snap to its normal position, allowing the door to close completely and latch the lock.

In the normal operation of the device, the cylinder i is secured on a door jarnb as by plate i5, and the plate 'i of the lever Si is secured on the door, the device being mounted longitudinally of the floor.

The air vent i3 is adjusted to meet the requirements of the particular door and the device is ready for use.

When the door is opened the lever is swung about its pivot 5 and bears against the roller i0 forcing the roller ahead of the lever toward the slotted end of the cylinder. The roller l being attached to the block 26 pulls the block and the piston P therewith, against the tension of the spring 3l.

When the door reaches its open position, having passed through an arc of approximately 90, the notch 8 engages the roller il] and the door is maintained in open position by the tension of spring 3l.

When the ydoor is released, the spring tends to force the piston toward the valved end of the cylinder, and the air in the piston. chamber is compressed and forced slowly through the air vent I8.

As the door approaches its closed position, the iange 25' of the piston head disk 25, reaches and passes over the by-pass 32. As soon as the rear or trailing edge of the flange 25' passes the rear end of the by-pass, the air compressed by the piston on its return to normal position, rushes through the by-pass and rearward of the piston head. The air pressure is thus released and the spring snaps to its extended position, and the door is urged to closed position in such a manner as to assure the positive engagement of the lock to latch the door.

From the foregoing it is believed apparent that my improvement precludes the usual inefficient closing of doors by the usual spring lever and pneumatic closers, which when used in the normal manner often fail to completely close the door due to the lack of force at the end of the piston stroke, to overcome the tension of the look spring.

As set forth above, my device permits the piston, toward the end of its stroke, to vcomplete its movement with a snap suiicient to overcome the spring tension of the lock, and thereby cornpletely close and latch the door.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

l. In a door closer the combination with a slotted pivotallymounted cylinder having an interior annular shoulder, and a perforated washer at one side of the shoulder, of a slotted block reciprocable in the cylinder and located at the other side of the shoulder, said annular shoulder forming a stop for the washer and for the block, a piston in the pivotal end of the cylinder, a stem for the piston passing through the Washer and Xed to the block, a spring interposed between the piston and the washer, an angular lever having a rigid pivotal mount adjacent one side of the cylinder and passing through the slotted cylinder and the slotted block and a pivotal connection for the other end of the lever mounted on the cylinder at its opposite side.

2. In a door closer, the combination with a slotted pivotally mounted cylinder having an interior annular flange, and a perforated washer at one side oi the flange, of a slotted block reciprooable in the cylinder at the other side of the flange, a piston in the pivotal end of the cylinder, said ycylinder having an obliquely extending depression forming a bly-.pass of greater length than the width of the piston, a piston stem passing through the washer and xed to the block, a spring interposedbetween the piston and washer, an angular lever having a rigid pivotal mount adjacent one side of the cylinder and passing through the slotted cylinder and the slotted block, an anti-friction guide roller for the lever journaled in the slotted block, and a pivotal connection for the other end of the lever mounted on the cylinder at its other side.

LEROY C'ORNWELL. 

